.bottom-nav {
  width: 100%;
  height: 40px;
  display: flex;
  justify-content: space-between;

  position: fixed;

  left: 0;
  bottom: 0;
}

.bottom-nav a {
  text-decoration: none;
  display: inline-block;
  flex: 1;
  text-align: center;
  line-height: 40px;
  border-top: solid 2px #444;
}

.bottom-nav a.active {
  border-top: solid 2px orangered;
  background-color: orangered;
  color: white;
}